Microbiome of the Queensland Fruit Fly through Metamorphosis

Abstract

Bactrocera tryoni (Froggatt) (Queensland fruit fly, or “Qfly”) is a highly polyphagous tephritid fruit fly and a serious economic pest in Australia. Qfly biology is intimately linked to the bacteria and fungi of its microbiome. While there are numerous studies of the microbiome in larvae and adults, the transition of the microbiome through the pupal stage remains unknown. To address this knowledge gap, we used high-throughput Next-Generation Sequencing (NGS) to examine microbial communities at each developmental stage in the Qfly life cycle, targeting the bacterial 16S rRNA and fungal ITS regions. We found that microbial communities were similar at the larval and pupal stage and were also similar between adult males and females, yet there were marked differences between the larval and adult stages. Specific bacterial and fungal taxa are present in the larvae and adults (fed hydrolyzed yeast with sugar) which is likely related to differences in nutritional biology of these life stages. We observed a significant abundance of the Acetobacteraceae at the family level, both in the larval and pupal stages. Conversely, Enterobacteriaceae was highly abundant (>80%) only in the adults. The majority of fungal taxa present in Qfly were yeasts or yeast-like fungi. In addition to elucidating changes in the microbiome through developmental stages, this study characterizes the Qfly microbiome present at the establishment of laboratory colonies as they enter the domestication process.

Fruit host-dependent fungal communities in the microbiome of wild Queensland fruit fly larvae

“…Additionally, six replicate samples of fruit tissue (fruit flesh) (1-2 mg mass) were collected from the same fruit used to collect larvae (36 fruit samples in total). 40,44,45 .…”

“…in artificial larval diet significantly reduced the mean time from egg hatch to adult emergence of the Qfly 42 . In addition, significant variation in bacterial communities and their abundance has been found across developmental stages of the Qfly 43,44 . In contrast with this literature focusing on bacteria, just two studies have attempted to identify the mycobiome of the Qfly, with both using traditional culture-dependent methods to isolate fungal strains 45,46 .…”

Artificial Larval Diet Mediates the Microbiome of Queensland Fruit Fly

“…Colony was established in 2017 from infested fruits (Majumder et al, 2020). Briefly, infested Pomegranate Punica granatum, Green Apple Malus pumila and Quince Cydonia oblonga were collected from different geographic locations in the Australian states of New South Wales (NSW) and Victoria (VIC) ( Table 1).…”

“…For sample processing, Qfly larvae, pupae and adult flies (male and female separately) from the G5 colonies were surface sterilized using 0.5% Tween 80 (Sigma-Aldrich, St. incubated at 32 and 35 • C for 24 to 48 hr (Majumder et al, 2019(Majumder et al, , 2020. Immediately after the sterilization process, the guts of adult flies were dissected using a stereomicroscope (Leica MZ6 stereo-microscope, Leica R , Wetzlar, Germany).…”

“…PCR amplification and sequencing were performed by the Australian Genome Research Facility, University of Adelaide, Plant Genomics Centre, Hartley Grove, URRBRAE, SA 5064, AU. For bacterial identification, the V1-V3 16S rRNA region was amplified using primers 27F (5 AGAGTTTGATCMTGGCTCAG-3 ) and 519R (3 GWATTACCGCGGCKGCTG-5 ) (Lane, 1991) as used previously in Majumder et al (2019Majumder et al ( , 2020 . The resulting amplicons were measured using a fluorimeter (Thermo Fisher Scientific, North Ryde, NSW, Australia) and normalized (Fouts et al, 2012).…”